There are many advantages to backpacking through foreign lands over other types of travel:

• Anyone who isn't being chauffered to the airport, and plans to use local transportation once they've reached their travel destination, will find it easier to sling their belongings onto their back than drag them behind in a suitcase. And suitcases with wheels look dorky.
• These days backpacks are made to help travellers be organized, building in lots of handy pockets, compartments, loops and lashes. 
• Provided you haven't packed a Ming vase, you'll appreciate the fact that your backpack can be squeezed into places that a suitcase can't.
• Many packs come with zip-off day packs, which means you don't have to put a day pack into the precious space inside your backpack. Day packs are great for shorter excursions when you don't want or need all of your stuff with you (e.g., when you're going to the beach).
• Packs have uses besides luggage-toting. For example, they can be a stool to sit on or a pillow for your head in a time of need.

There are a few tricks to be learned if you're planning to backpack. Here are a few:

• Pack heavy items as high in your pack as possible, and toward the centre. This will save you from back aches.
• Put your work address, not your home address, on your luggage tags. There have been reports of thieves getting addresses from luggage tags because they know the luggage owner is on the road.
• Keep items that you will frequently use accessible -- near the opening or in an exterior pocket.
• Don't put your camera in your backpack. It would be heartbreaking to lose your luggage and your snapshots. Plus, we've all seen how airline luggage handlers treat our bags (sigh).
• If possible, choose a pack that opens at the top and the bottom, or all along the side. This will prevent you from having to stick your arm blindly into the belly of your pack and randomly fish items out.
• Consider packing a combination lock or padlock so that you don't have to have your pack with you every minute of the day. This is useful even in situations where, say, you're at a hostel in a shared room and you need to leave your pack to take a shower.
• It's also handy to have tiny locks hold the zippers of your pack shut. This won't stop anyone with real time and determination to steal your stuff, but it will certainly slow down pickpockets, etc, who may try to quickly unzip your pack as you're walking through a crowd.
• Small plastic bags, especially of the zip-lock variety. Don't leave home without them! After all, you wouldn't want to put a wet bathing suit, towel or pair of smelly socks in your pack along with clean, dry clothes. Would you?
• Try to buy a pack that has flaps to cover external zippers and other openings. This will help ensure that your stuff will stay dry if you're out in rain or snow.
• If the pack fits, wear it! Spend the money to buy a pack that fits your body. Investigate the available packs carefully. Salespeople can be helpful, and so can experienced travellers.
• Don't overpack. You don't REALLY need your rubber boots if you have sandals. You don't really need a sweater if you've packed a sweatshirt already. And remember to leave room for souveneirs!
• At the airport, insist on having a large plastic bag to put your pack into. On my last trip a fellow traveller's souveneir bottle of maple syrup opened and wrecked my new pack. Luckily, the airline agreed to clean it for me at their expense.